It's very subjective for me. Whatever makes an emotional connection. Sometimes it a pure tone, sometimes it a subtle detail that I've never noticed and sometimes it's a recalled memory from simpler times. Kind of like drinking good wine. Once you get used to something good, it's hard to go back.
I've been looking down the rabbit hole recently and I Imagine it's like gambling for some. Not every financial gamble pays off but when you get the occasional emotional reward, it's enough to keep you going back.
A dedicated 20A line and Furutech GTX-D outlet are scheduled for this week. Just one more fix and i'm done:).